It should be noted that reference to the prior art herein is not to be taken as an acknowledgement that such prior art constitutes common general knowledge in the art.
Leaking wellhead gas and wellhead fluids are a major environmental problem in gas and oil fields with consequent great concerns now held for the carbon foot print created by each wellhead and the potential health risks to workers and local residents.
Often gases and fluids spill from the wellhead. Early containment practice of such spills consisted of digging a pit around the wellhead. Environmental and regulatory concerns effectively discouraged such practice, leading to the need for alternate means to contain gas and liquid spilled from the wellhead. To date, devices and methods used to contain excess gas and fluid spilled from a wellhead have suffered from several drawbacks. For example, such devices and methods generally obstruct the area around the wellhead thereby interfering with servicing and may include pans that require assembly at the well site or are cumbersome to install. Also, where pumping means are used to transfer contained gases or liquids away from the wellhead, such means involve electrical or internal combustion drives which, for safety reasons, must be located some distance away from the wellhead.
Numerous gas wells have been found to leak around the outer conductive pipe. In one test conducted by the Safety and Health Division of the Department of Employment, Economic Development and Innovation, Queensland, Australia, May 2010, “58 wells were tested at one of the Queensland Surat Basin gas fields. Of those wells, 26 were found to be leaking, including one of which was well over the explosive limit, four that were at or over the 10% over the limit, and twenty-one that had minor leaks.” As a result of these test results, a new Queensland Government Code of Practice for detecting and managing gas emissions at CSG well sites was enacted. “Companies must now immediately fix leaks that fall over the reportable level, even those which may have a very low volume of gas and report those leaks to the Government's Petroleum and Gas Inspectorate.” Note the current number of gas wells drilled in Queensland as at March, 2013 is around 3,000 with another 40,000 planned to be drilled in Queensland gas fields.
World-first research from two scientists at Southern Cross University, New England, Australia, has found methane levels in the air and water in areas where coal seam gas mining has taken place are up to 10 times the methane levels found in unmined areas. Dr Isaac Santos and Dr Damian Maher, scientists attached to the Southern Cross University, Armidale, NSW, Australia, took thousands of air and water samples from gas fields near Tara in Southern Queensland, Australia and compared them with samples from the Northern Rivers region, New South Wales, where a number of coal seam gas wells have been proposed. They found methane levels in creeks around Tara, Queensland, Australia, were up to 10 times higher than in the Northern Rivers, New South Wales and up to three times higher in the atmosphere. Tara residents have been complaining of previously unknown illnesses. ABC Tue Dec. 18, 2012 10:20 am AEDT:—“A Western Downs community group in southern Queensland says more families are now reporting health problems they believe are caused by nearby coal seam gas (CSG) fields.” Another health concern is the presence of the radioactive gas “Radon” which can be present in coal seam gas.
Another potential form of contamination occurs from surface water around a wellhead due to leaching of contaminants either from the drilling operations, ie. fracking, or from accidental spillage during operation and maintenance of the wellhead, ie. oil, grease and well water.
Clearly it would be advantageous if a system and method for the detection and containment of leaking gas and fluids from around wellheads could be devised that helped to at least ameliorate some of the shortcomings described above. In particular, it would be beneficial to create a fugitive gas and effluent detection and collection system which overcomes one or more of the above problems thereby significantly mitigating both environmental and personal safety risks and significantly reducing the carbon footprint of each gas wellhead and/or provide the consumer with an effective risk management plan and commercial means to reduce the potential loss of commercial quantities of gas at some wellheads that would have been otherwise lost.